Amazon reports to have resolved the problem. We're not observing any instability for last 20 minutes. We're closing the incident, but we'll continue monitoring the situation.

Trading Bots system is up again, but some trading bots had been stopped by the system via the consistency health check mechanic (since they have missed a check or two). We'll notify everyone who's affected individually.

An update from Amazon:

 We can confirm that some instances within a single Availability Zone (USE2-AZ1) in the US-EAST-2 Region have experienced a loss of power. The loss of power is affecting part of a single data center within the affected Availability Zone. Power has been restored to the affected facility and at this stage the majority of the affected EC2 instances have recovered. We expect to recover the vast majority of EC2 instances within the next hour.

Amazon (AWS), who is our major cloud infrastructure provider, is experiencing a networking system incident. This incident can potentially affect a wide range of subsystems, but at the moment the only sub-system which is impaired is Trading Bots.